Air pollution from coal-fired power plants

Air pollution from coal-fired power plants is large and varied and contributes to a significant number of negative environmental and health effects. When coal is burned to generate electricity, the combustion releases a combination of toxic chemicals into the environment, and thus the human body. A November 2009 report on the effects of coal by the Physicians for Social Responsibility found that coal combustion affects not only the human respiratory system, but also the cardiovascular and nervous system.

A 2011 report by the the American Lung Association found that coal-fired power plants produce more hazardous air pollution in the United States than any other industrial pollution sources. A 2004 report by the Clean Air Task Force estimated that soot pollution from power plants contributes to 24,000 premature deaths, 38,200 non-fatal heart attacks, and tens of thousands of hospital visits and asthma attacks each year.

Pollutants
Coal combustion releases nitrogen oxides, sulfur dioxide, particulate matter (PM), mercury, and dozens of other substances known to be hazardous to human health.

Aging coal plants "grandfathered" in after passage of the Clean Air Act have been particularly linked to large quantities of harmful emissions.

Such emissions include:

Nitrogen oxides (NOx). The release of oxides of nitrogen (nitrogen oxides and nitrogen dioxides [NO2]) reacts with volatile organic compounds in the presence of sunlight to produce ground-level ozone, the primary ingredient in smog. Nitrogen oxide also contributes to fine particulate matter, or soot. Both smog and soot are linked to a host of serious health effects. Nitrogen oxide also harms the environment, contributing to acidification of lakes and streams (acid rain).

Sulfur dioxide (SO2). Sulfur dioxide contributes to the formation of microscopic particles (particulate pollution or soot) that can be inhaled deep into the lungs and aggravate respiratory conditions such as asthma and chronic bronchitis, increasing cough and mucous secretion.

Mercury (HG). Coal contains trace amounts of mercury that, when burned, enter the environment and human bodies, effecting intellectual development.

Particulate matter (PM), also known as particle pollution, includes the tiny particles of fly ash and dust that are expelled from coal-burning power plants. Fine particles are a mixture of a variety of different compounds and pollutants that originate primarily from combustion sources such as power plants, but also diesel trucks and buses, cars, etc. Fine particles are either emitted directly from these combustion sources or are formed in the atmosphere through complex oxidation reactions involving gases, such as sulfur dioxide (SO2) or nitrogen oxides (NOX). Among particles, fine particles are of particular concern because they are so tiny that they can be inhaled deeply, thus evading the human lungs' natural defenses.

Smog is the chemical reaction of sunlight, nitrogen oxides (NOx), and volatile organic compounds (VOCs) in the atmosphere, which leaves airborne particles (particulate matter) and ground-level ozone (smog). Ground level ozone is an invisible gas made of three oxygen atoms (O3).

Black carbon, also called soot, arises from sources such as diesel engine exhaust, burning biomass, cooking fires, and coal plants. It is made up of tiny carbon particulate matter that contributes to global warming by absorbing heat in the atmosphere and reducing albedo, the reflection of sunlight, when deposited on snow and ice. It is also a big component of air pollution around the world.

CO2 and air pollutants
Carbon dioxide (CO2) is the most significant greenhouse gas that contributes to global warming. The dangers of global warming include disruption of global weather patterns and ecosystems, flooding, severe storms, and droughts. A warming climate will also extend the range of infectious diseases. Coal combustion is responsible for more than 30% of total U.S. carbon dioxide pollution.

A 2009 study, “Enhancement of Local Air Pollution by Urban CO2 Domes,” published in Environmental Science & Technology by Mark Z. Jacobson, found that domes of increased carbon dioxide concentrations – discovered to form above cities more than a decade ago – cause local temperature increases that in turn increase the amounts of local air pollutants, raising concentrations of health-damaging ground-level ozone as well as particulate matter in urban air.

According to Jacobson: "Warming increases water vapor, and both water vapor and higher temperatures increase ozone where the ozone is already high but have less effect where the ozone is low. Carbon dioxide domes over cities increase temperatures over the cities above and beyond the heat island effect, and these higher temperatures increase water vapor, and both higher water vapor and higher temperatures increase the rates of chemical air pollution production over cities relative to rural areas. The results suggest a causal nature of increased air pollution mortality due to increased carbon dioxide where the air pollution is already high. Thus, controlling CO2 emissions at the local level will reduce air pollution and the resulting air pollution mortality."

Jacobson’s estimates that “reducing local CO2 may reduce 300-1000 premature air pollution mortalities/yr in the U.S. and 50-100/yr in California, even if CO2 in adjacent regions is not controlled.”

Respiratory Effects
Pollutants produced by coal combustion act on the respiratory system to cause a variety of respiratory ailments. Air pollutants such as nitrogen oxides (NOx) and fine particulate matter (i.e. PM2.5) adversely affect lung development, reducing forced expiratory volume (FEV) among children. Reduced FEV often precedes the subsequent development of other pulmonary diseases.

Air pollution triggers attacks of asthma, which now affects more than 9% of all U.S. children, who are particularly susceptible to the development of pollution-related asthma attacks. Asthma exacerbations have been linked specifically to exposure to ozone, a gas produced when NOx reacts with volatile organic compounds in the presence of sunlight and heat. The risk to children of experiencing ozone-related asthma exists even when ambient ozone levels fall within the limits set by the EPA.

Coal pollutants also plays a role in the development of chronic obstructive pulmonary disease (COPD), a lung disease characterized by permanent narrowing of airways. COPD is the fourth leading cause of mortality in the U.S. Coal pollutants may also cause COPD exacerbations, in part through an immunologic response—i.e., inflammation. PM exposure disposes the development of inflammation on the cellular level, which in turn can lead to exacerbations of COPD.

Exposures to ozone and PM are also correlated with the development of and mortality from lung cancer, the leading cancer killer in both men and women.

According to the American Lung Association, particle pollution can damage the body in ways similar to cigarette smoking, helping explain why particle pollution can cause not just lung disease, but heart attacks and strokes. However, even short-term exposure to particle pollution can kill: peaks or spikes in particle pollution can last for hours to days. Deaths can occur on the very day that particle levels are high, or within one to two months afterward.

Cardiovascular Effects
Air pollution is known to negatively impact cardiovascular health. The mechanisms have not been definitively identified, but studies in both animals and humans suggest they are the same as those for respiratory disease: pulmonary inflammation and oxidative stress. Pollutants produced by coal combustion can lead to cardiovascular disease, such as artery blockages leading to heart attacks, and tissue death and heart damage due to oxygen deprivation.

Recent research suggests that nitrogen oxides and PM2.5, along with other pollutants, are associated with hospital admissions for potentially fatal cardiac rhythm disturbances. Cities with high NO 2 concentrations have death rates four times higher than those with low NO 2 concentrations, suggesting a potential correlation.

There are also cardiovascular effects from long-term air pollution exposure. Exposure to chronic air pollution over many years increases cardiovascular mortality, a correlation that remains significant even while controlling for other risk factors like smoking. Conversely, long-term improvements in air pollution reduce mortality rates: reductions in PM2.5 concentration in 51 metropolitan areas, due to the Clean Air Act, were correlated with significant increases in life expectancy.

Nervous System
According to the PSR report, the nervous system is also a target for coal pollution’s health effects, as the same mechanisms thought to mediate the effect of air pollutants on coronary arteries also apply to the arteries that nourish the brain. These include stimulation of the inflammatory response and oxidative stress, which can lead to stroke and other cerebral vascular disease.

Several studies have shown a correlation between coal-related air pollutants and stroke. In Medicare patients, ambient levels of PM2.5 have been correlated with cerebrovascular disease, and PM10 with hospital admission for ischemic stroke, which accounts for eighty-seven percent of all strokes.

Coal contains trace amounts of mercury that, when burned, enter the environment and can act on the nervous system to cause loss of intellectual capacity. Coal-fired power plants are responsible for approximately one-third of all mercury emissions attributable to human activity. Researchers have estimated that between 300,000 and 630,000 children are born in the U.S. each year with blood mercury levels high enough to impair performance on neurodevelopmental tests and cause lifelong loss of intelligence.

2011 American Lung Association report on health effects
In March 2011, the American Lung Association released the report, "Toxic Air: The Case for Cleaning Up Coal-fired Power Plants," on the hazardous air pollutants emitted from power plants. Key findings from the report included:


 * Coal-fired power plants produce more hazardous air pollution in the United States than any other industrial pollution sources;
 * More than 400 coal-fired power plants located in 46 states across the country release in excess of 386,000 tons of hazardous air pollutants into the atmosphere each year;
 * Particulate matter pollution from power plants is estimated to kill approximately 13,000 people a year. Most coal-fired plants are concentrated in the Midwest and Southeast.

2010 report on health costs from US coal plants
A 2010 report from the Clean Air Task Force, The Toll From Coal found that, in the United States, particle pollution from existing coal power plants is expected to cause some 13,200 premature deaths in 2010, as well as 9,700 additional hospitalizations and 20,000 heart attacks.

Estimated mortality figures for 2010 have Pennsylvania leading the nation with 1,359 premature deaths, 1,016 people admitted to the hospital, and 2,298 additional heart attacks. Ohio comes in second with 1,221 additional premature deaths; New York takes third with 945 dead from coal pollution. Per capita, the figures change slightly: West Virginia is first in the nation, with an estimated 14.7 coal-related deaths per 100,000 adults. Pennsylvania and Ohio tie for second, with 13.9; Kentucky comes in third at 12.6.

The report found that the total monetized value of these adverse health impacts amounts to more than $100 billion per year. This burden is not distributed evenly across the population. Adverse impacts are especially severe for the elderly, children, and those with respiratory disease. In addition, the poor, minority groups, and people who live in areas downwind of multiple power plants are likely to be disproportionately exposed to the health risks and costs of fine particle pollution.

In the previous version of this study, done in 2004, it was estimated that coal pollution would caused about 24,000 premature deaths annually. The authors cited EPA action in 2005 under the Clean Air Interstate Rule (CAIR) as resulting in the declining mortality figures. Though CAIR was struck down in Federal court in 2008, the pollution reduction requirements remain in effect until a replacement is established. In making their projections, the authors of the study assume similarly stringent requirements will be in place for the remainder of 2010.

Even with much decreased numbers, the report says sulfur dioxide and nitrogen oxide emissions from coal power plants will "continue to take a significant toll on the health and longevity of millions of Americans." Overall, the report says "among all industrial sources of air pollution, none poses greater risks to human health and the environment than coal-fired power plants."

Related SourceWatch articles

 * Health effects of coal
 * Climate impacts of coal plants
 * Mercury and coal
 * Sulfur dioxide and coal
 * Global warming
 * Environmental impacts of coal
 * External costs of coal
 * Federal coal subsidies
 * Estimating U.S. Government Subsidies to Energy Sources 2002-2008
 * Retrofit vs. Phase-Out of Coal-Fired Power Plants
 * Coal waste
 * Coal sludge
 * Fly ash
 * Heavy metals and coal
 * United States and coal